Nd_xEr_(5-x)Si_3系列化合物晶体结构和磁性研究  

Crystal Structures and Magnetic Properties of Nd_xEr_(5-x)Si_3 Compounds

作　　者：韩文泽[1] 焦学胜[1] 杜红林[2] 刘蕴韬[1] 陈东风[1] 孙凯[1] 郭浩[1] 

机构地区：[1]中国原子能科学研究院核物理研究所,北京102413 [2]北京大学物理学院,北京100871

出　　处：《中国稀土学报》2014年第5期636-640,共5页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(11205249;11105232)资助

摘　　要：利用电弧熔炼制备了NdxEr5-xSi3（x=0-5）系列化合物样品。通过X射线粉末衍射分析和磁性测量研究了Nd替代Er对Er5Si3化合物结构和磁性的影响。研究结果表明：随着Nd替代量的增加,其晶体结构、相组成及磁性能发生了明显变化。低Nd含量时（x≤3）,样品具有Mn5Si3型六角结构,空间群为P63/mcm,样品具有反铁磁性。虽然奈尔温度不遵循De Gennes定律,但能被RKKY理论完美解释。高Nd含量时（x=5）,样品具有Cr5B3型四方结构,空间群为I4/mcm,对外显示铁磁性。Nd含量为x=4时,两种结构共存,Rietveld精修表明Mn5Si3型结构占58（1）%,Cr5B3型结构占42（1）%。其磁化率温度曲线在50-100 K具有铁磁性特征,但随着温度的进一步下降,又显示出反铁磁性的特征,暗示其内部存在着铁磁相和反铁磁相的耦合。The crystal structures and magnetic properties of NdxEr5_xSi3 compounds have been studied by X-ray powder diffraction and magnetic measurements. The main results showed that the crystal structures and magnetic properties change apparently with increasing Nd concentration. For 0 ≤x≤3, the samples NdxEr5_xSi3 are MnsSi3- type structure with antiferromagnetism at low temperature. The N6el temperature does not obey De Gennes＇ law, but it could be explained by RKKY theory. While x =4, the sample is mixture with about 58% Mn5Si3-type phase and 42% Cr5B3-type phase. The susceptibility versus temperature curve indicated that there exists interaction be- tween ferromagnetism and antiferromagnetism. While x =5, Nd5Si3 is single phase of Cr5B3-type structure with fer- romagnetism.

关 键 词：Er5Si3 晶体结构 磁性 稀土 

分 类 号：O493.4[理学—物理]